Human dignity in antiquity was commonly a marker of the status a person enjoyed in society. The higher the social position, the more dignified the person, making dignity to be contingent and ephemeral. By contrast, the Stoics taught that dignity was not so much a sign of social position as a description of the personal qualities, the excellence, of individuals. A person possessed dignity to the extent that he possessed and manifested virtue, regardless of social position. In the modern era, however, is more often associated with an individual's membership in the human species and thought to be a value attached to persons commanding a minimum of respect without regard to social status or personal characteristics. Justifications for this view may be philosophical, such as the Kantian argument that grounds dignity in the autonomy of human persons as rational agents, or theological, such as the Christian argument that grounds dignity in the status of persons as creatures made in the image of God. While the idea has critics, the assumption of human dignity imposes duties on business, which must respect the dignity of customers, employees and communities.